Fig.ii



D. J. KONEVAL MICRO MODULAR RESONATOR PACKAGE Sept. 28, 1965 Sheets-Sheet 1 Filed Nov. 26, 1962 F'IG.6 FIG INVENTOR. DONALD J.'KONEVALAT TOR NEY I lllll |||l k W E;

cl o b FIG.8

54 i E:] T0 GROUND p '2s,19es D. J. KQNEVAL 3,209,178

MICRO MODULAR RESONATOR PACKAGE Filed NOV. 26, 1962 .2 Sheets-Sheet 2INVENTOR.

DONALD J. KONEVAL ATTORNEY United States Patent 3,209,178 MICRO MODULARRESONATOR PACKAGE Donald J. Koneval, Cleveland, ()hio, assignor toClevite Corporation, a corporation of Ohio Filed Nov. 26, 1962, Ser. No.239,971 14 Claims. (Cl. 310-91) This invention relates to fabrication ofelectric circuit components and more particularly to an improvedstructure and method for packaging micro modular filters.

The invention is particularly applicable to the packaging of miniaturepiezoelectric resonators, particularly the miniature wafer type utilizedin filter circuits. Such miniature resonators may, for example, be ofdisk-shaped configuration with a diameter less than 0.05 inch and athickness less than 0.008 inch. It will be apparent that the size ofsuch resonators has necessitated the use of a supporting structure or apackage having provision for connection in an electric circuit.

It is often desired to connect a number of miniature resonators in apredetermined circuit arrangement to form a specific type of filter.Five such resonators may be connected, for example, to form aconventional ladder type filter. To achieve optimum circuitminiaturization the resonators utilized in a single band-pass filter,such as the ladder filter, are placed in a single package havinginternal electrical connections between the various resonators toestablish the filter configuration. One package which has been usedextensively for a multi-resonator filter comprises a body wafer platehaving circular cavities in which resonator disks are placed along withresilient contact disks. The body wafer is enclosed by cover plateswhich have printed circuit electrode means on the surface thereof forelectrical contact with the contact disks. The cover plates are attachedby an epoxy adhesive and exert a predetermined pressure on the resonatorcontact disk to insure electrical contact and to resiliently support theresonator disks.

The above described package is typical of a prior art filter package.Such a package, while serving its intended purpose, has been found topossess certain limitations and disadvantages which affect the accuracyand the manufacturing cost of the filter. Perhaps the most seriousdisadvantage is the fact that variations in contact pressure causingvariations in the resonant frequency of the resonator occur if thedimension of all parts of the package are not maintained to highprecision tolerances. For example, in the case of the above describedpackage a vari ation in contact disk dimensions or a variation in coverplate adhesive thickness will affect the contact pressure and result ina frequency or impedance variation. Thus,

extremely high dimensional accuracy must be maintained.

A second disadvantage of the described prior art package is the factthat the circuit of the filter is not complete until the cover platesare attached, prohibiting circuit testing prior to complete assembly ofthe package. If an electrical defect is then discovered it cannot beremedied without destruction of the package during disassembly.Accordingly, the fabrication cost has been exceedingly high.

It is a principal object of this invention to provide an improvedcomponent package possessing ease of assembly and having a lowfabrication cost.

Another object of the invention is to provide a package for miniaturecircuit components which enables the characteristics of the componentsto be tested prior to complete assembly of the package.

Another object of the invention is to provide an improved micro modularfilter package requiring less dimensional accuracy than prior artpackages.

In one preferred embodiment of the invention a filter package comprisesa wafer supporting plate having a plurality of slots extending betweenopposite face surfaces of the plate. A resonator disk and resilientcontacts are positioned in each of the slots. Electrode means comprisingelectrically conductive material is fixed by an adhesive to one facesurface of the plate and electrically connected to the resilientcontacts within the slots to establish the desired filter configuration.Top and bottom covers plates are attached to the face surfaces of thesupporting plate. The cover plates do not provide electrodes for thefilter circuit nor affect the contact pressure on the resonators,permitting the electrical characteristics of the resonators to be testedand determined prior to complete assembly of the package.

Other objects and advantages will become apparent from the followingdescription taken in connection with the accompanying drawings, wherein:

FIGURE 1 is a perspective view of an assembled filter package embodyingthe invention;

FIGURE 2 is an exploded perspective view of the parts of the filterpackage illustrated in FIGURE 1;

FIGURES 3, 4, 5, 6 and 7 are enlarged details of parts shown in FIGURE2;

FIGURES 8 and 9 are sections taken along the line 88 of FIGURE 2illustrating the method of inserting the resonator disks;

FIGURE 10 is a circuit diagram illustrating the equivalent circuit ofthe filter package disclosed in FIGURES -1 through 9;

FIGURE 11 is a top view of a part shown in FIGURE 2 illustrating theaddition of shielding;

FIGURE 12 is an exploded perspective view illustrating a secondembodiment of the filter package;

FIGURE 13 is an enlarged detail of a part shown in FIGURE 12;

FIGURE 14 is a fragmentary sectional view taken across slot 84- ofFIGURE 12;

FIGURE 15 is an exploded perspective view illustrating still anotherembodiment of the invention;

FIGURES 16 and 17 are enlarged details of parts shown in FIGURE 15; and

FIGURE 18 illustrates a multiple package filter assembly.

Referring to FIGURE 1 of the drawings, there is shown an assembled micromodular filter package identified generally by the reference numeral 10.For purposes of clarity the assembled package in FIGURE 1 is illustratedapproximately ten times its actual size.

The package 10 comprises, as shown more clearly in FIGURE 2, a mainsupporting plate or wafer 12 having an upper cover plate 14 and a bottomcover plate 16, all of which are formed from suitable electricallynon-conductive material. The supporting plate 12 is provided with .aplurality (in this case five) of spaced slots 18, 20, '22, 24 and 26 ofrectangular cross-section and extending between the opposite facesurfaces of the supporting plate 12 in perpendicular relationshiptherewith. The slots 18, 20, 22, 24 and 26 may be formed, for example,by ultrasonic machining or other known fabrication techniques applicableto miniature components.

A plurality of resonators (in this case five) 28, 30, 32, 34 and 36 arereceived by the slots 18, 20, 22, 24 and 26, respectively, and maycomprise, for example, ceramic disk-shaped piezoelectric wafers havingelectrodes on op posite surfaces thereof. As is well known to thoseskilled in the art such resonators have a resonant frequency dependenton the wafer and electrode dimensions and may be variously polarized toachieve various modes of vibrations, such as, for example, a radialvibrational mode. Since the construction and function of the resonators28, 30, 32, 34 and 36 form no part of the present invention, furtherdescription is deemed unnecessary.

The upper surface of plate 12 is provided with elecslots in supportingplate 12 and have the configurations illustrated in FIGURES 3, 4, 5, 6and 7, respectively, prior to installation. The foil segments 38, 39,40, 42 and 44 may be fabricated to the configurations illustrated inFIGURES 3-7 by a photoetching process and then applied by epoxy adhesiveor other suitable means to the upper surface of plate 12. Each foilsegment is provided with integrally formed contact portions which extendinto the associated resonator slot to establish electrical contactaccording to the electrode pattern.

Referring specifically to the foil segment 38 illustrated in FIGURE 3,this electrode segment is provided with an integral end contact portion46 which upon positioning of segment 38 on-the surface of plate 12 isbent downwardly along the dashed line into the slot 18 for subsequentcontact with one side of disk 28 upon insertion of the same. The otherend of segment 38 extends beyond the edge of plate 12 to provide onecircuit connector for the filter package.

Foil segment 39, illustrated in FIGURE 4, is similarly provided with anintegral contact portion 48 which is bent downwardly along the dashedline for insertion into slot 20 and an extending opposite end defining asecond circuit connector for the filter package.

Foil segment 40, as shown in FIGURE 5, is provided with integral contactportions 50 and 52 which are bent along the dashed lines for insertioninto slots 22 and 24, respectively, and an integral portion 54 adaptedto extend beyond the edge of supporting plate 12, as shown in FIG- URE2, to provide the third circuit connector for the filter package 10.

Foil segment 42 (FIGURE 6) is similarly provided with integral resonatorcontact portions 56, 58 and 60 for insertion in the same manner in slots18, 22 and 26, respectively, and foil segment 44, identical inconfiguration to segment 42, is likewise provided with contact portions62, 64 and 66, for insertion into slots 20, 24 and 26, respectively.

When the foil segments 38, 39, 40, 42 and 44 are fixed in position asillustrated in FIGURE 2, two foil contact '9 which is a sectional viewsimilar to FIGURE 8, of slot 24, after installation of resonator 34. Asshown in FIG- URE 9, the foil contact portions in each slot assume aslightly curved configuration and exert a slight contact pressure on theresonators to resiliently support the same and insure good electricalcontact with the electrodes. It will be apparent that the contactpressure is dependent only on the slot width and dimensions of the foilcontact portions.

After installation of the foil segments and resonators in the slots asdescribed above, the circuitry of the filter 'is complete and thefrequency response of the filter comprised of resonators 28, 30, 32, 34and 36 may be checked by means of appropriate electrical test equipmentprior to attachment of top and bottom cover plates 14 and 16. This is animportant feature since a defective resonator or a resonator subjectedto poor contact pressure may be located and readily removed or thecondition remedied without damage to the package or electrode means.Inasmuch as the contact pressure on each resonator disk is determinedonly by the slot width and dimensions of the foil contact portions,subsequent attachment of the cover plates 14 and 16 does not alter theelectrical characteristics of the filter. Accordingly, the filterpackage provides ease of assembly and testing heretofore unachieved.

After the frequency response of the filter section has been tested thecover plates 14 and 16 are attached to the upper and'lowe-r surfaces ofsupporting plate 12 by a suitable epoxy adhesive to produce theassembled package illustrated in FIGURE 1 with the circuit connectors38, 39 and 54 extending as illustrated.

In FIGURE 10 there is illustrated the equivalent electrical circuit ofthe filter package 10. Each of the resonator disks 28, 30, 32, 34 and 36is shown by its equivalent parallel resonant circuit comprising aninductance (it) having a predetermined series capacitance (b) and ashunting capacitance (c). The circuit connectors 38, 39 and 54 have beendiagrammatically illustrated as input, output and ground connectors, torender obvious the circuitry of the foil electrodes shown in FIGURE 2.It will be apparent that the electrode pattern and filter circuitconfiguration may be varied as desired by variation in theconfiguration, number and arrangement of the foil electrode elrnents.Thus the specific ladder type filter arrangement of the resonators andelectrode segments described is disclosed only for purposes ofillustration.

It will also be apparent that the dimensions and size of the partsutilized will vary with the size and number of resonators employed. Forpurposes of illustration and not of limitation, however, it has beenfound that the following dimensions are suitable for the partsillustrated in FIGURES l-9 for a five element ladder filter utilizing Inthe case of several filters assembled from parts of the above listeddimensions for operation at 4.3 megacycles, the individual resonatorswere found to undergo only an average change in resonant frequency andanti-resonant frequency of 0.06 percent. Accordingly, the error intro-.dued by the assembly of the package was found to be negligible.

In FIGURE 11 there is shown the supporting plate 12 with the addition ofshielding to minimize interaction between the series and parallelresonators of the filter circuit disclosed. The shielding meanscomprises additional foil segments 70 and 72 of triangular configurationand attached to the face surface of plate 12 in the same manner as foilsegments 38, 39, 40,42 and 44. The foil segment 72 is provided with aground connector as shown and foil segment 74 is electrically connectedto foil segment 40 or formed integrally therewith as shown when circuitconnector 54 is connected to ground. The shielding means comprisingsegments 70 and 72 is not necessary for satisfactory performance butdoes produce optimum stop band rejection.

slots 76, 78, 80, 82 and 84 arranged in the configuration shown toreceive resonator disks 86, 88, 90, 92 and 94, respectively. Theelectrode means comprises, in this instance, a printed circuit 96 on theupper face surface of plate 74 and interconnecting the resonator slotsto estab lish an electrode pattern for a five element ladder type filterhaving the equivalent circuit illustrated in FIGURE 10. In thisembodiment foil contact segments 98 of the configuration illustrated inFIGURE 13 are utilized to electrically connect the printed circuit meanswith the resonators as illustrated in FIGURE 14 which is a sectionalview of slot 84 with resonator disk 94 inserted. Each foil contactsegment 98- is fixed by electrically conductive epoxy adhesive or othersuitable means to the printed circuit on the face surface of plate 12 asshown in FIGURE 12 with an end portion bent along the dashed line shownin FIGURE 14 and extending into the asso ciated slot.

At the edges of the supporting plate 12 foil segments 98, 100 and 102are similarly attached by electrically conductive epoxy adhesive orother suitable means to the printed circuit to provide circuitconnectors for the package. As is apparent from the electrode pattern ofthe printed circuit 96, the filter package illustrated in FIG- URES 12,13 and 14 also comprises a five element ladder type filter circuit asshown schematically in FIG- URE 10.

In FIGURES 15, 16 and 17 there is illustrated a single resonatorpackage, which utilizes foil electrode segments similar to theembodiment of FIGURES 19. In this embodiment a supporting plate 104 isprovided with a single centrally disposed slot 106 which receives aresonator disk 108. The electrode means comprises two foil segments 110and 112 which are illustrated in detail in FIG- URES 16 and 17,respectively. Foil segment 110 as illustrated in FIGURE 16 comprises anintegral circuit connector 114 and a resonator contact portion 116adapted to be bent along the dashed line for insertion into slot 106 forsubsequent electrical contact with one side of resonator disk 108.Segment 112 similarly comprises an integral circuit connector 118 forthe package and comprises a contact portion 120 for insertion into slot106. The foil segments 110 and 112 are attached to the upper surface ofsupporting plate 104 by an epoxy adhesive or other suitable means withcontact portions 114 and 120 positioned in slot 106 to engage oppositesides of disk 108 in the manner described with respect to the individualslots of the embodiment disclosed in FIGURES 1-9.

FIGURE 18 illustrates a multiple package filter formed by stacking anumber of filter packages similar to those hereinbefore described toform a more complex filter circuit or to merely provide a common supportfor a plurality of individual filter packages. From top to bottom thereis illustrated three supporting packages 122a, 122b and 1220 adapted tobe attached together by adhesive in stacked relationship to form amultiple package assembly. The packages 122a, 12211 and 1220 maycomprise any of the embodiments hereinbefore described. For purposes ofillustration, however, the multiple package is depicted in FIGURE 18 ascomprising three packages of the type disclosed in FIG. 2 andcorresponding parts have been given like reference numerals withappropriate suffixes a, b and c.

The individual circuit connectors of packages 122a, 122b and 1220 may bevariously interconnected as desired to provide different filter circuitconfigurations or connected to separate circuits as desired to provideindependent commonly supported filter packages.

It will be apparent, in connection with FIGURE 18, that only one coverplate need be provided between adjacent supporting plates. For example,as between packages 122a and 122b, either the bottom cover plate 16a ofpackage 122a or the upper cover plate 14b of package 122!) may beomitted. Similarly, only one plate need be provided between packages122b and 1220.

The disclosed embodiments and illustrated applications of the inventionare exemplary of a few of the many modifications which are possible. Itwill be apparent that the invention provides a filter package possessingease of assembly and which permits appropriate circuit testing of thefilter prior to scaling or complete assembly of the package andtherefore accomplishes the objects of the invention.

While there have been described what at present are believed to be thepreferred embodiments of this invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention, and it is aimed,therefore, to cover in the appended claims all such changes andmodifications as fall within the true spirit and scope of the invention.

What is claimed and desired to be secured by United States LettersPatent is:

1. A package for a circuit component comprising: a supporting member ofinsulating material having at least one slot extending from a facesurface of said member in substantially perpendicular relationship tosaid face surface for receiving the circuit component; electrode meansfor the circuit component on said face surface including contact meanswithin said slot adapted to be engaged by the component; and a covermember of insulating material attached to said face surface to enclosesaid electrode means and said slot.

2. A resonator package comprising: a supporting plate of insulatingmaterial having a slot extending substantially perpendicular from oneface surface thereof; a piezoelectric resonator disk positioned in saidslot in substantially perpendicular relationship with said face surface;electrode means on said face surface and including contact meansextending into said slot for electrical contact with said resonatordisk; and a cover plate of insulating material attached to said facesurface.

3. A resonator package as claimed in claim 2 wherein said electrodemeans comprises segments of electrically conductive foil materialadhered to said face surface and said contact means comprises integralcontact portions extending from said foil segments into said slot; saidfoil segments additionally having integral circuit connector portionsextending beyond the edge of said supporting plate.

4. A resonator package as claimed in claim 2 wherein said electrodemeans comprises a printed circuit on said face surface and said contactmeans comprises segments of electrically conductive foil materialadhered to said printed circuit at the edges of said slot and extendinginto said slot for electrical contact with said resonator disk.

5. A resonator support package comprising: a supporting plate ofinsulating material having at least one slot extending perpendicularlybetween oppositely disposed face surfaces of said plate; a piezoelectricresonator disk positioned in said slot and having electrodes on oppositesides thereof; a pair of resilient electrically conductive foil contactsegments extending into said slot on opposite sides of said resonatordisks to engage said electrodes respectively and to resiliently supportsaid disk within said slot; electrode means on one face surface of saidsupporting plate electrically connected to said foil segments; and coverplates of insulating material fixed to said opposite face surfacesrespectively of said supporting plate.

6. A resonator support package as claimed in claim 5 wherein saidelectrode means comprises a printed circuit.

7. A resonator support package as claimed in claim 5 wherein saidelectrode means comprises electrically conductive foil material formedintegrally with said contact segments.

8. A filter package comprising: a supporting plate of insulatingmaterial having a plurality of spaced slots extending between theoppositely disposed face surfaces of said plate; a plurality ofresonator disks positioned in said slots respectively and each defininga plane perpendicular to the face surfaces of said supporting plate;electrode means on one face surface of said plate electricallyconnecting said resonator disks in a predeterminedv filterconfiguration; external circuit connecting means for said electrodemeans at the extremity ofsaid supporting plate; and cover plates ofinsulating material fixed by adhesive to the opposite face surfaces ofsaid sup: porting plate to seal the same.

9. A filter package as claimed in claim 8 further including shieldingmeans adhered to the face surface of said supporting plate for shieldingthe series and shunt resonator disks in said filter circuitconfiguration to prevent interaction between the same.

10. A filter package comprising: a rectangular supporting plate ofinsulating material having a plurality of spaced slots extending betweenoppositely disposed face surfaces of said plate; a plurality ofresonator disks positioned in said slots respectively and each defininga plane perpendicular to the face surfaces of said supporting plate; apair of resilient electrically conductive foil segments extending intoeach of said slots on pposite sides of the resonator disk therein toelectrically contact the disk and to resiliently support the same withinthe slot; a printed circuit on one face surface of said plateelectrically connected to said contact segments and operative to connect.said resonator disk in a predetermined circuit filter configuration;circuit connecting foil segments adhered to said printed circuit at theextremity of said supporting plate; and cover plates of insulatingmaterial fixed by adhesive to the opposite face surfaces of saidsupporting plate to seal the same.

11. A filter package comprising: a supporting plate of insulatingmaterial having a plurality of spaced slots extending between oppositelydisposed face surfaces of said plate; a plurality of resonator diskspositioned in said slots respectively; a plurality of foil segmentsfixed by adhesive to the face surface of said plate and having integralportions extending into said slots to resiliently contact opposite sidesof said disks to connect said disks in a predetermined filterconfiguration; said foil segments having integral portions extendingbeyond the extremity of said plate to define external circuitconnectors; and cover plates of insulating material fixed by adhesive tothe oppositely disposed face surfaces of said supporting plate to sealthe same.

12. A filter package comprising: a resonator supporting plate ofinsulating material having a plurality of spaced slots extending betweenthe oppositely disposed face surfaces of said plate; a plurality ofresonator disks positioned in said slots respectively; means forming anelectrode pattern on one of said face surfaces electrically connectingsaid disks in a predetermined filter configuration; and cover plates ofinsulating material attached to said face surfaces respectively toenclose said supporting plate and disks.

13. A filter package comprising: an assembly comprising a plurality ofstacked supporting plates each having at least one slot extendingsubstantially perpendicular from one face surface thereof; resonatordisks positioned in said slots; electrode means for each resonator diskon said one face surface of each of said supporting plates; and top andbottom cover plates fixed to said assembly to enclose the same.

14. A filter package comprising: an assembly comprising a plurality ofstacked supporting plates each having at least one slot extendingsubstantially perpendicular from one face surface thereof; resonatordisks positioned in said slots; electrode means for each resonator diskon said one face surface of each of said supporting plates; insulatingplates between adjacent supporting plates; said insulating plates andsupporting plates being fixed together by adhesive to provide a sealedpackage.

References Cited by the Examiner UNITED STATES PATENTS 2,177,629 10/39Foster 3 l09.1 2,327,487 8/43 Bach 3109.7 2,434,266 1/48 Fruth et a1310-97 2,771,663 11/56 Henry 3109.1

MILTON o. HIRSHFIELD, Primary Examiner.

1. A PACKAGE FOR A CIRCUIT COMPONENT COMPRISING: A SUPPORTING MEMBER OFINSULATING MATERIAL HAVING AT LEAST ONE SLOT EXTENDING FROM A FACESURFACE OF SAID MEMBER IN SUBSTANTIALLY PERPENDICULAR RELATIONSHIP TOSAID FACE SURFACE FOR RECEIVING THE CIRCUIT COMPONENT; ELECTRODE MEANSFOR THE CIRCUIT COMPONENT ON SAID FACE SURFACE INCLUDING CONTACT MEANSWITHIN SAID SLOT ADAPTED TO BE ENGAGED BY THE COMPONENT; AND A COVERMEMBER OF INSULATING MATERIAL ATTACHED TO SAID FACE SURFACE TO ENCLOSESAID ELECTRODE MEANS AND SAID SLOT.